The invention described herein relates to methods of fabricating a semiconductor device, and more particularly, to methods of fabricating a semiconductor device including a phase change layer.
Semiconductor devices using phase change materials are increasingly used. For example, a unit cell of a phase change memory device may include a phase change material for storing data. The resistivity of a phase change material may change depending on its phase. That is, the phase change material may have a lower resistivity in a crystalline phase than in an amorphous phase. Such characteristics of the phase change material may be used to store/read data in/from the phase change memory cell.
The phase of a phase-change material may change depending on the temperature of supplied heat and/or the heat supply duration. For example, if heat corresponding to a melting point is supplied to a phase change material for a short time, the phase change material may change into an amorphous phase. On the contrary, if heat of about a crystallization temperature is supplied to a phase change material for a long time, the phase change material may change into a crystalline phase.
In general, heat energy may be used to change the phase of a phase change material. A phase change memory device may utilize a large amount of current to generate high-temperature heat. Consequently, the power consumption of the phase change memory device may increase, which may increase the difficulty of highly integrating the phase change memory device.